They can already stand, walk, wriggle under obstacles, and change colors. Now researchers are adding a new skill to the soft robot arsenal: jumping.
Using small explosions produced by a mix of methane and oxygen, researchers at Harvard have designed a soft robot that can leap as much as a foot in the air. That ability to jump could one day prove critical in allowing the robots to avoid obstacles during search and rescue operations. The research is described in a Feb. 6 paper in the international edition of Angewandte Chemie.
"Initially, our soft robot systems used pneumatic pressure to actuate," said Robert Shepherd, first author of the paper, former postdoctoral researcher in the Whitesides Research Group at Harvard, and now an assistant professor at Cornell. "While that system worked, it was rather slow — it took on the order of a second. Using combustion, however, allows us to actuate the robots very fast. We were able to measure the speed of the robot's jump at 4 meters per second."
Just as with other soft robots, the three-legged jumping system begins life as a mold created by a 3-D printer. The robots are molded using soft silicone that allows them to stretch and flex.
But where pneumatic robots are connected to tubing that pumps air, the jumping robots are connected to tubes that deliver a precisely controlled mix of methane and oxygen. Using high-voltage wires embedded in each leg of the robot, researchers deliver a spark to ignite the gases, causing a small explosion that sends the robot into the air.
Among the key design innovations that allowed the combustion system to work, Shepherd said, was the incorporation of a simple valve into each leg of the robot.
"We flow fuel and oxygen into the channels, and ignite it," Shepherd said. "The heat expands the gas, causing the flap to close, pressurizing the channel and causing it to actuate. As the gas cools, the flap opens and we push the exhaust out by flowing more gas in. So we don't need to use complex valve systems, all because we chose to mold a soft flap into the robot from the beginning."
While the notion of using combustion to power a soft robot was enticing, it also came with a number of critical questions, not the least of which was whether the soft silicone used to create the robots would even survive.
"It's a lot more powerful, but the question we had to answer was whether it was compatible — were the temperatures compatible — with this system," Shepherd said. "What we were able to show is, because the duration of the explosion is so short, the energies absorbed by the robot are small enough to be compatible with soft robots. What's more, the temperature of the robot increases by, on average, less than one kelvin."
While he hopes to see internal combustion systems developed that can allow robots to walk or even run, Shepherd said jumping made sense as a starting point."Because it releases so much energy so fast, it made sense for jumping to be the first 'gait' we explored with this system," he said. "The next step now is to learn how we can use this combustion system for other gaits, like running or even walking."
Other authors on the paper are Adam Stokes, Jacob Freake, Phillip Snyder, Aaron Mazzeo, Ludovico Cademartiri, Stephen A. Morin, George M. Whitesides, the Woodford L. and Ann A. Flowers University Professor at Harvard, and Jabulani Barber, an FAS research associate with the Whitesides Research Group.
Peter Reuell | EurekAlert!
TU Graz researchers show that enzyme function inhibits battery ageing
21.03.2017 | Technische Universität Graz
New nanofiber marks important step in next generation battery development
13.03.2017 | Georgia Institute of Technology
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
22.03.2017 | Materials Sciences
22.03.2017 | Physics and Astronomy
22.03.2017 | Materials Sciences